This invention relates to balers for forming cylindrical bales (commonly referred to as "round" bales) and more particularly relates to a cylindrical baler with an ejector for moving a bale during discharge sufficiently rearwardly of the baler so that the discharge gate of the baler may be closed without hitting the discharged bale. Also, the invention relates to a method for discharging a bale with such an ejector.
Prior art cylindrical balers generally include a rear bale discharge gate pivotably mounted to a front portion of the baler frame. A bale is discharged from such a machine by pivoting the discharge gate rearwardly and upwardly permitting the bale to drop directly onto the ground or by first pivoting the discharge gate upwardly and rearwardly and then activating a lower conveyor on which the bale rests during formation in the bale forming chamber of the baler. The lower conveyor urges the bale rearwardly out of the machine and onto the ground. With both designs, the bale generally comes to rest underneath the discharge gate. According to one commonly used method for operating such cylindrical balers after the bale has been discharged, the operator pulls forward a short distance so that the discharge gate may be closed without hitting the discharged bale. In order to be able to pull forward without disturbing the windrow in front of the baler and possibly over feeding the baler when the baling operation is resumed, the operator must backup a few meters before discharging a bale. This is a tedious and time consuming procedure. If it is not executed properly, there is a possibility that the gate, when closed, may rest on top of the bale. This may damage the baler or even cause it to turn over.
Other equally disadvantageous prior art methods for discharging a bale are described in the Background of the Invention of U.S. Pat. No. 4,206,587.
Certain solutions have been proposed to simplify the procedure for discharge of cylindrical bales. In U.S. Pat. No. 4,206,587, a cylindrical baler with a resiliently mounted transverse bar for rearwardly propelling a bale as it is discharged from the chamber of the baler is disclosed. With the action of the resiliently mounted bar, the bale is propelled with sufficient force to roll the bale rearwardly of the baler a sufficient distance so that the discharge gate of the baler may be closed without moving the baler forwardly. Also, in U.S. Pat. Nos. 4,208,862 and 4,218,866 a cylindrical baler with a bale forming chamber defined by plurality of reversably driven chains is disclosed. The chains are driven in a first direction during the bale forming operation and then are automatically reversably driven during the bale discharge operation to impart a rearwardly directed top spin to the bale as it is discharged from the bale forming chamber. The top spin carries the bale away from the baler a sufficient distance so that the baler does not have to be driven forwardly to permit the closing of the discharge gate. Both of these approaches present certain inherent disadvantages. Both approaches provide a rearwardly directed top spin to the bale as it is discharged from the bale forming chamber. The rearward motion of the bale is uncontrolled. If the baling operation is taking place in a hilly area, the bale may roll down a hill and could position the bale in a location where it would be difficult to retrieve. Furthermore, because, with varying crop conditions, the weight of the bale may vary from one bale to the next during the baling operation, the amount of energy imparted to the bale may need to be varied from one bale to the next. With the foregoing designs, such variation is not possible.
In accordance with U.S. patent application, Ser. No. 294,651 entitled ROUND BALER WITH DISCHARGE GATE FOR REARWARDLY MOVING A BALE, filed on Aug. 20, 1981 in the name of Viaud and assigned to the assignee of the invention herein, a cylindrical baler with an improved mechanism for moving a bale rearwardly of the discharge gate following discharge of the bale from the bale forming chamber is disclosed. The discharge gate includes at least a portion of the belts or chains which define the bale forming chamber and a pump for driving the belts or chains in a direction opposite to that used for bale formation. The gate is further operable to bring a portion of the belts or chains into contact with a discharged bale and to displace the bale rearwardly from the baler along the ground by imparting a controlled rearward rolling action to the bale. Such a baler provides a solution to many of the problems associated with the prior art balers discussed above. However, such a baler still suffers from certain limitations. For example, the belts defining the bale forming chamber must be tensioned in order to apply rolling action to the bale following discharge. Second, mechanism for driving the belts in reverse must be provided. Third, the height of the gate must be properly adjusted so that the belts contact the bale. All of these requirements add complexity to the baler. In addition, if the baler is ejecting a bale on a hill with the baler headed downhill, the bale may not be moved entirely free of the gate due to the tendency of the bale to roll toward the baler.